San Diego County, San Diego Rat Control Situation:
Hi David, Is a UV blacklight still useful, exterior-wise, if it rains after the rodents leave their urine stains? I am in the process of performing exterior maintenance to better exclude my roof rats. 1) I have a 25 year old cedar shake roof in San Diego California with openings under each shake along the rake edge of the roof at the gable ends of my house. There's no drip edge, i.e. under the shakes I have roofing paper (now somewhat curled) that runs more or less up to and rests right atop the fascia board. Because I have skip sheathing, and since the cross section of a shake is a wedge that is up to one inch at the upper, thick end, this appears to create many huge entry points along the rake edges even though the sheathing is rabbeted into the fascia board. As a result, I'm thinking of getting a UV blacklight to use outside the house to sleuth for urine stains along the upper edge of the gable end shakes and fascia boards. My question is, how easily does the winter rain wash away the urine, rendering this a pointless exercise? 2) I noticed a new product called "rat-out gel" and was thinking of applying it along the rake edges mentioned above. Or, maybe I should just buy many rolls of X-Clude and use that instead. Or maybe both. Any comment? Thanks very much for your website, Doug
My response: First off, I do not have experience using UV lights to detect rat urine. But I do suspect that rain will severely limit the effectiveness of this approach. I have never heard of Rat-Out Gel or XClude, but I typically stick to physical barriers rather than repellent type devices. If your roof makes this impossible, you might have a tough time keeping the rats out.
San Diego Rat Control Tip of The Week
Norway Rat Biology
The Norway rat is typically nocturnal. It is a good swimmer; however, unlike the related black rat, it is a poor climber. Norway rats burrow well, and regularly uncover broad tunnel systems.
Rats are equipped for creating ultrasonic vocalizations, both as grown-ups and babies. They may likewise transmit short, high frequency, socially-prompted vocalization during interaction with different rats or animals. This call most takes after a trilling sound but is undetectable to human ears. Rats can discernibly be heard through calls sounding like squeaks when they are in trouble.
These rats are omnivores. This implies they can eat both plants and animals. As predators, rats are opportunistic.
The Norway rat can breed consistently if the conditions are reasonable, and a female can deliver up to twelve litters in a year. The gestation period is just 21 days, and litters can number up to fourteen, albeit smaller litters are common. In this way, the rat population can increase rapidly. Rats have a lifespan of around three years, yet regularly live less than one year.
Norway rats live in enormous hierarchical groups, either in tunnels or subsurface places, such as sewers and basements. When food is hard to come by, the rats lower in the social order are the first to die. If a large portion of a rat populace is eliminated from a zone, the rest will expand their reproductive rate, and rapidly reestablish the old populace level. This makes it imperative to have a plan to get rid of the entire rat population on your property if an infestation occurs.
